Process for the production of a powdered composition, the powdered composition obtained thereby and uses thereof

ABSTRACT

The present invention relates to a process for the production of a powdered composition from a liquid composition comprising fat, protein or both, to the powdered composition obtained thereby and products containing said powdered composition.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the US National Stage (371) of InternationalApplication No. PCT/EP2012/001412, filed Mar. 30, 2012, which claimspriority to International Application No. PCT/EP2011/001633, filed Mar.31, 2011. The disclosures of each are herein incorporated by referencein their entirety.

FIELD

The present invention relates to a process for the production of apowdered composition from a liquid composition comprising fat, proteinor both, to the powdered composition obtained thereby and productscontaining said powdered composition.

BACKGROUND OF THE INVENTION

The use of spray-drying is a known method for the production of powderedcompositions, such as powdered nutritional formulas. Different processesare known for preparing such spray-dried products. Prior art processesare for instance described in Food Product Design (May 1997): “Spraydrying: innovative use of an old process” by R. C. Deis. WO 94/28993 A1discloses a modified drying process using superheated steam in thedrying medium.

NL 8602710 discloses a method for producing a food product in powderform whereby a starch-containing starting material present in form of aslurry is steam heated and dried and whereby the slurry is dispersed bysteam injection.

However, it is still a continuous aim to increase the productioncapacity for powdered nutritional formulas, for example infant milkformulas. An increased capacity will allow a factory to produce morepowder and to reduce the production cost per quantity of producedpowder. However, increasing the process capacity regularly results innegative side effects. Negative side effects very often include adecreased quality of the powder. For example, infant formula powdershould have a good wettability, that means a short time that powderstays on the surface of water before dissolving, a limited amount ofwhite flecks, which are protein precipitates visible on the inside of amilk bottle after emptying, and a good bulk density. A reliable andreproducible bulk density in the process is particularly important aspreparing a nutrition from a powdered composition is usually done byadding a predefined volume of a powdered composition to a liquid. Forexample, for infant nutrition usually a given number of scoops perbottle is added. Deviations in bulk density of the powder can disturbthe concentration of nutrients or nutrient requirements of the infant.

Furthermore, the negative effects of heat should be limited, i.e. theoccurrence of Maillard reaction products should be limited sinceMaillard reaction products are undesired in the powder.

Thus, a technical problem underlying the present invention is to providemethods and means for overcoming the disadvantages associated with theprocesses in the state of the art.

A further technical problem underlying the present invention is toprovide cost-effective methods to produce with an increased productioncapacity powdered compositions, especially powdered compositionscontaining fat, protein and carbohydrates, for instance powderednutritional formulas, with high quality.

A further technical problem underlying the present invention is toprovide powdered compositions, especially powdered compositionscontaining fat, protein and carbohydrates, which exhibit improvedproperties, in particular improved technological, functional and/ororganoleptic properties and methods to produce them.

SUMMARY OF THE INVENTION

The present inventors have found a way to increase the productioncapacity of the powder production process, while maintaining good oreven improved powder characteristics. Accordingly, the present inventionprovides for a process for the production of a powdered composition, inparticular powdered nutritional product, from a liquid composition,using a spray-drying process wherein both air and steam, preferably inform of a mixture thereof, are used to atomize a liquid composition.

A particular contribution of the present invention to the art is theincrease of production capacity of powders by feeding a highlyconcentrated liquid composition in the powder manufacturing process,while retaining good powder characteristics. Obviously, productioncapacity can also be increased by scaling up a manufacturingprocess—that means this increases the weight of powder that can beproduced. However, this is not cost effective as also the weight ofwater that has to be evaporated increases. Hence, in the art it ishighly desirable to increase production capacity by increasing the drymatter concentration of the liquid composition.

The present invention solves its technical problem in particular byproviding the subject matter of the claims and especially by providing amethod according to claim 1.

In the present process, a liquid composition, preferably a concentratedliquid mixture, from which for instance infant formula powder ismanufactured, is fed through an inlet nozzle, preferably a pressurenozzle, into a mixing chamber comprising gas, in particular air, andsteam, thereby atomizing the liquid mixture. Preferably, in the mixingchamber itself, no drying process takes place. This first atomizationstep is followed by a second atomization step, wherein the atomizedmixture of liquid composition, steam and gas, in particular air, exitsthe mixing chamber through an outlet nozzle. In a preferred embodiment,the mixture can exit the mixing chamber into a drying chamber, forinstance a spraying tower, wherein the composition is dried, resultingin a powder. A main benefit of the present process is the increase ofthe production capacity of the process, since the solids content of theliquid composition can be very high, resulting in an improved productioncapacity, while the resulting powder displays very particular andadvantageous characteristics. Furthermore, the present process allows areliable, controllable and reproducible production of powder withdesired properties, in particular bulk density.

The present inventors first recognized that using a first atomisationstep wherein 100% steam is introduced into the mixing chamber is notsufficient to provide a production capacity increased process forobtaining high quality powder. In fact, steam is usually introduced forquickly heating the liquid composition by condensation of the steam ontothe atomized liquid composition. The temperature increase of the liquidcomposition improves the atomisation of the liquid composition. However,using 100% steam results in undesired powder quality, for example due toundesirable Maillard reactions caused by overheating. Additionally,atomizing with 100% steam results in significant amounts of condensedsteam, which in turn needs to be evaporated in a drying chamber. Theevaporation of water requires extra energy, thereby increasing costs andreducing capacity of the powder manufacturing process. Furthermore, ahigh humidity in the drying chamber causes fouling of the chamberresulting in decreased capacity.

On the other hand, using 100% air does not give the desired resulteither. In particular, the resulting powder does not have the desiredquality, for example displays a variable bulk density. Furthermore, theproduction capacity of the process is too low. Without wishing to bebound by theory, the reduced production capacity and/or product qualityis believed to be due to the lack of a non-evaporative zone in themixing chamber, when using air only. The outside of a forming dropletdries very quickly, forming a small “crust” around at least a part ofthe droplet, thereby disturbing the atomization of the product. When thenon-evaporative zone is lacking, the surface of the droplet increases inviscosity, thereby impairing atomisation.

DETAILED DESCRIPTION

Thus, the present invention solves its technical problem in particularby a process for the production of a powdered composition from a liquidcomposition comprising fat, protein or both, which process comprises: a)a first atomising step, wherein the liquid composition and (i) gas andsteam or (ii) a mixture of gas and steam are fed into a mixing chamberand wherein the feeding of liquid composition is conducted by sprayingit through an inlet nozzle into the mixing chamber so as to obtain afirst mixture, b) a second atomising step, wherein the first mixtureexits said mixing chamber through an outlet nozzle, so as to obtain asecond mixture and c) drying the second mixture so as to obtain thepowdered composition.

In the context of the present invention a “liquid composition” is meantto refer to a fluid medium, preferably an aqueous fluid medium, as afirst component, comprising a second component, namely fat, protein orboth, that means fat and protein. Said liquid composition may be in theform of a solution, suspension or emulsion. Preferably, the liquidcomposition comprises protein, fat, carbohydrates, vitamins andminerals. Preferably, the liquid composition comprises long chainpolyunsaturated fatty acids, preferably docosahexaenoic acid (22:6;n-3), more preferably docosahexaenoic and arachidonic acid (20:4; n-6),more preferably fish oil. It was found that the present process can beadvantageously used to manufacture a powder with such oils.

The liquid composition is preferably an emulsion.

In the context of the present invention the term “comprising” is meantto have the same meaning as “containing” or “including”. The presentliquid composition preferably also contains carbohydrates. In oneembodiment, however, the term “comprising” is also understood to havethe meaning of “consisting of”, hereby excluding the presence of furthercomponents in said composition.

In the context of the present invention a “powdered composition” refersto a composition composed of particles, in particular fine particles, inparticular those which are not cemented together. Thus, a composition inpowder form is a composition in a particle form.

In the present invention the term “nozzle” refers to a mechanical deviceable to control the direction and/or characteristics of a fluid flow, inparticular of a liquid composition, as it exits or enters an adjacentchamber or pipe via an orifice. In the context of the present inventionthe term “nozzle” does not include said adjacent chamber or adjacentpipe, but solely refers to the control device comprising the orifice.

According to the process of present invention, the inlet nozzle ispreferably a pressure nozzle or prefilming nozzle, preferably pressurenozzle. The outlet nozzle is preferably a two fluid nozzle.

In a furthermore preferred embodiment of the present invention thenozzle is a pressure nozzle, in particular a single fluid pressurenozzle, preferably an atomizer nozzle.

“Steam” is according to the present invention a mist or gas phase ofwater, that means water vapour. In the present process, preferably thegas phase of water is used. Preferably, superheated steam is used.Superheated steam is steam at a temperature higher than its boilingpoint at a given pressure. Preferably, the steam consists of gasiform ormisty water. Preferably, the steam is pure steam, in particular steamwhich is free of air. The steam can also be saturated steam, that meanssteam which is in equilibrium with liquid water.

The gas used in the present process is preferably air, an inert gas or amixture thereof, preferably air or nitrogen or a mixture thereof, mostpreferably air. The present inventor found that even with air, thepresent process gives a high capacity and good powder characteristics.The term “air” as used in the present invention refers to a gaseousmixture, comprising nitrogen, oxygen and argon. Preferably, the presentprocess uses the air as present in the earths atmosphere comprisingabout 78 volume % nitrogen and 21 volume % oxygen and about 1 volume %other substances including argon and carbon dioxide.

The terms “atomization” and “atomizing” as used in the present inventionrefers to separating a liquid composition into particles, preferably theseparation occurs mainly by (i) shear; and/or (ii) turbulence resultingfrom a gas flow.

In the context of the present invention the equilibrium temperaturepreferably is the thermal equilibrium temperature and is meant to referto the temperature of a system comprising at least two components beingin thermal contact with each other and wherein there is no net exchangeof energy between the components resulting in a single system, whereineach of the components have the same temperature, meaning that the wholesystem has a single temperature.

In the mixing chamber, the liquid composition is mixed with steam andgas, preferably air. The liquid composition is fed into the mixingchamber via an inlet nozzle, preferably a pressure nozzle. Theintroduction or feeding of the liquid composition under pressure througha nozzle results in a first atomization of the liquid composition.

The present process is preferably an industrial process, and ispreferably adapted for that. In the present process, preferably, theliquid composition is sprayed into the mixing chamber at a flow-ratefrom 250 to 700 kg/hour.

The gas, preferably air, and the steam can be fed into the mixingchamber in combination or separately from each other. In a preferredembodiment, the steam and the gas, preferably air, is fed into themixing chamber separately from each other, so that the settings of themixing process can be favourably controlled. Preferably, the steam andthe gas, preferably air and steam, can be fed together into the mixingchamber, preferably in form of a mixture.

In a preferred embodiment of the present invention, steam and gas,preferably air, is fed separately from each other into the mixingchamber and separately from the liquid composition.

In a preferred embodiment of the present invention, steam and gas,preferably air, is fed in combination into the mixing chamber andseparately from the liquid composition.

In a preferred embodiment of the present invention specific ratios ofgas, preferably air, to steam in the gas-steam mixture, preferablyair-steam mixture, present in the mixing chamber result in aparticularly high production capacity of the process, while retaining aparticularly good powder quality of the resulting product. This isbelieved to be due to the good equilibrium temperature (Tequi) in themixing chamber and/or the reduced need to evaporate water, while havingsufficient steam for good heat transfer to the particles by condensationof the steam and the formation of a non-evaporative zone.

Preferably, the weight ratio of gas:steam, preferably air:steam, presentin the mixing chamber is from 1:0.5 to 1:25, measured as weight per timesegment, for example measured as weight per hour. More preferably, theweight ratio of gas:steam, preferably air:steam, present in the mixingchamber is from 1:1 to 1:20, and even more preferably from 1:1 and 1:15,measured as weight per time segment. Preferably, the weight ratio ofgas:steam, preferably air:steam, present in the mixing chamber is from1:5 to 1:15, measured as weight per time segment, for example around1:8.

The weight ratio of gas:steam:liquid composition, preferablyair:steam:liquid composition, present in the mixing chamber ispreferably 0.5 to 5 (gas, preferably air):2 to 15 (steam):100 (liquidcomposition) (weight/hour).

The liquid composition has preferably a temperature from 55 to 90° C.when sprayed into the mixing chamber. This enables a particularly goodatomization.

It was found that the gas, preferably air, and steam feed are preferablybe arranged so that the equilibrium temperature in the mixing chamber isbelow 159° C., preferably below 155° C., more preferably below 150° C.,preferably the equilibrium temperature in the mixing chamber is at least100° C., more preferably at least 120° C. Preferably, the equilibriumtemperature in the mixing chamber is from 90° C. to 155° C. Morepreferably, the equilibrium temperature in the mixing chamber is from100° C. to 155° C., even more preferably from 120° C. to 155° C., evenmore preferably from 125° C. to 150° C.

The equilibrium temperature in the mixing chamber can for example befrom around 125° C. to around 155° C.

This provides a good powder quality, while keeping heat damage limited.Heat damage can be measured for example by the determination of thewhite fleck number.

The liquid composition according to the present invention comprises fat,protein or fat and protein. The liquid composition can additionallycomprise carbohydrates. The liquid composition comprises preferably fat,protein and carbohydrates.

Preferably, the liquid composition has a dry matter content of at least55 weight %, more preferably of at least 60 weight %, even morepreferably of at least 62 weight %.

Preferably, the liquid composition has a dry matter content from 55 to75 weight % (based on total weight of the liquid composition).Preferably the liquid composition has a dry matter content from 55 to 70weight % based on total weight of the liquid composition, morepreferably from 58 to 65 weight %. Preferably, the liquid compositionhas a dry matter content from 60 to 75 weight % (based on total weightof the liquid composition), more preferably from 60 to 69 weight %, forexample of around 65 to around 67 weight %.

The highly concentrated liquid composition with a preferred dry mattercontent from 55 to 70 weight % preferably results in an increase of theproduction capacity of factory by about 5 to 40%. Spray drying of aliquid composition comprising for instance protein, fat andcarbohydrates can be used to obtain a powder providing nutrition to asubject, preferably after dissolving it in a liquid such as water. Theliquid composition, preferably, comprises 20 to 35, preferably 22 to 32wt % fat based on dry weight of the liquid composition, i.e. without thewater. The liquid composition preferably comprises 10 to 25, preferably17 to 22 wt % protein based on dry weight of the liquid composition. Theliquid composition has preferably a fat content of 20 to 35 weight %(based on dry weight of the liquid composition) and a protein content of10 to 25 weight % (based on dry weight of the liquid composition).

It was also found that the length of the mixing chamber is preferablylimited. With a long mixing chamber, a unexpected pulsating behaviourcan occur, which can make it more difficult to properly dry the productfor example in a drying chamber and potentially results in a powder ofreduced and inconsistent quality. The mixing chamber for use in thepresent invention, preferably, has a length of 2 to 10 cm, preferably 3to 8 cm.

The pressure in the mixing chamber is preferably from 2 to 10 bar, morepreferably from 5 to 7 bar. Such a preferred pressure in the mixingchamber ensures the ability to introduce steam at the proper temperatureand a good atomization when the mixture of air, steam and liquidcomposition exits the mixing chamber through an outlet nozzle to obtaina second mixture.

After the second atomizing step, wherein the heated first mixture exitsthe mixing chamber through an outlet nozzle, so as to obtain a secondmixture, the second mixture is dried, preferably fully dried, to obtainthe powdered composition. For drying conventional drying methods may beused, for example using a drying air flow in a drying chamber.

In a preferred embodiment of the present invention, the drying air flowmay be a co-current, a counter-current or a mixed air flow.

In a preferred embodiment the dried product is removed from the dryingair and preferably is collected in collection equipment.

In a furthermore preferred embodiment the dried product may be subjectedto further processing steps such as agglomeration leading toagglomerated products which in turn may also be dried.

The process according to the present invention results in a powderdisplaying a good quality, preferably with properties distinguishing thepresent powder from powder of the state of the art.

Therefore, the present invention refers also to a powdered compositionobtainable according to the process according to the present invention.

For a powdered composition, for example a nutritional powderedcomposition, it is important that it has a reproducible bulk density. Itwas found that with the present process a powder composition with areliable, controllable and/or reproducible bulk density can bemanufactured. This is very important, particularly for infant nutritionpowders. Infant nutrition is usually made by reconstitution of a powderusing a scoop. With a variable bulk density, the weight per scoop canvary, resulting in an inaccurate dosing of the powder, and the feedingof a suboptimal formula. Hence, maintaining a reliable bulk density isimportant in the art.

The powdered composition preferably comprises fat, protein or fat andprotein, preferably the powdered composition comprises fat and proteinand carbohydrates.

Preferably, the powdered composition has a bulk density of less than0.54 g/ml, more preferably of less than 0.50 g/ml. Preferably, thepowdered composition has a bulk density of more than 0.45 g/ml, morepreferably of at least than 0.47 g/ml. Preferably, the powderedcomposition has a bulk density of 0.35 to 0.51 g/ml. Preferably, thepowdered composition has a bulk density of 0.40 to 0.6 g/ml, morepreferably of 0.45 to 0.55 g/ml, even more preferably of 0.47 to 0.53g/ml, even more preferably of 0.47 to 0.50 g/ml.

In the context of the present invention, D [v, 0.5] is the volume (v)median diameter also referred to as D50 or D0.5 that means is thediameter value of the particle size in a given particle population,where the diameter of 50% of the particles in the population is belowthis value and 50% is above the value.

In the context of the present invention, the D [v, 0.1] is the diametervalue of the particle size in a given particle population, where thediameter of 10% of the particles in the population is below this valueand 90% is above the value.

In the context of the present invention, D [v, 0.9] is the diametervalue of the particle size in a given particle population, where thediameter of 90% of the particles in the population is below this valueand 10% is above the value.

In the context of the present invention, D [4.3] is the volume or massmoment mean or the De Broucker mean, in particular the volume mean. TheD [4.3] value is the arithmetic average of the particle population.

The powdered composition has preferably a particle size distribution D[4.3] which is in the range from 80 to 350 μm, in particular 130 to 220μm. The powdered composition has preferably a particle size distributionD [4.3] of at least 80 μm, preferably at least 100 μm.

The powdered composition has preferably a particle size distribution D[v, 0.1] which is in the range from 30 to 120 μm, preferably 40 to 110μm.

The powdered composition has preferably a particle size distribution D[v, 0.5] which is in the range from 80 to 320 μm, preferably 110 to 250μm, more preferably of 130 to 200 μm.

The powdered composition has preferably a particle size distribution D[v, 0.9] which is in the range from 200 to 700 μm, preferably 250 to 600μm.

The present invention also provides a nutritional product comprising thepowdered composition according to the present invention, preferably inan amount of 1 to 100, preferably 20 to 100, in particular 30 to 99,preferably 50 to 95 weight % (weight % based on total weight ofnutritional product). The present invention provides also a nutritionalproduct comprising the powdered composition produced in a processaccording to the present invention.

The nutritional product is preferably a food or feed product. Thenutritional product is more preferably a food product. The nutritionalproduct is more preferably an infant nutritional product. Thenutritional product comprises fat, protein or fat and protein,preferably the nutritional product comprises fat and protein andcarbohydrates.

Preferably, the present liquid composition or powder comprises lactose,preferably at least 75 wt. % lactose based on total weight of thecarbohydrates, more preferably at least 90 wt. %.

The present liquid composition and consequently powder compositioncomprise protein. The term protein according to this invention refers toproteinaceous material, including undenatured and denatured protein,peptides and amino acids. Preferably, the protein is obtained from cowmilk. Preferably, the present liquid composition of powder comprisesmilk protein (e.g. whey protein, casein), preferably whey protein,casein and/or milk protein concentrate, preferably at least 75 wt. %milk protein based on total weight of protein. Preferably, the presentliquid composition or powder composition comprises protein hydrolysate,preferably at least 75 wt. % protein hydrolysate based on total weightof the protein. Preferably, the protein hydrolysate is cow milk proteinhydrolysate.

Further preferred embodiments are the subject matter of the subclaims.

The invention will be further described by way of the non-limitingexamples at the accompanying figures.

It is shown in

FIG. 1 a schematically overview of the process according to the presentinvention;

FIG. 2 the steam and air flow at different equilibrium temperatures inthe mixing chamber;

FIG. 3 the bulk and particle density of powdered compositions producedaccording to the present invention and according to the state of the artas function of the equilibrium temperatures in the mixing chamberresulting form different steam/air ratios and

FIG. 4 SEM pictures of powdered compositions produced according to thepresent invention and according to the state of the art.

EXAMPLES Example 1

FIG. 1 shows a schematically overview over the process according to thepresent invention. FIG. 1 shows an apparatus 100 to conduct a processaccording to the present invention. The apparatus 100 comprises a mixingchamber 1, an inlet nozzle 2 and an outlet nozzle 3. Furthermore, theapparatus 100 comprises feed pipes 4 to feed a mixture of steam S andgas, in this example air A from a gas chamber 5 into the mixing chamber1. The apparatus 100 also comprises a drying chamber 6 for drying amixture coming through the outlet nozzle 3.

A liquid composition LC comprising fat and protein having a temperaturefrom 55 to 90° C. is sprayed in a first atomizing step through the inletnozzle 2 into the mixing chamber 1. The mixing chamber 1 is also fedwith a mixture of overheated steam and air so that a pressure of 5 to 10bar, for example around 6 bar, is present in the mixing chamber 1. Thesteam/air mixture creates a non-evaporative zone, where atomization ofthe liquid composition sprayed through the inlet nozzle 2 which can befor example a pressure nozzle, into the mixing chamber 1 takes placewithout simultaneous evaporation. This enables atomization at higherviscosities and thus higher dry matter contents. Therefore, the liquidcomposition can have for example a dry matter content of around 60 to68%-weight based on total weight of the liquid composition. The smallproduct droplets resulting from atomization are very quickly heated bycondensation of the steam on their surfaces. The driving force for thisheat transfer is a temperature difference between the liquid compositionand the steam. An equilibrium temperature is reached when the liquidcomposition has reached the steam temperature, which is determined bythe steam pressure in the mixing chamber 1. However, the inventors foundthat a minimum pressure of around 6 bar in the mixing chamber 1 ishelpful to get a good second atomization step using the outlet nozzle 3.However, a pressure of 6 bar would result in a steam saturationtemperature of 159° C. when using pure steam. This high temperature canlead to product damage.

When both steam and air are present, the steam saturation temperaturedepends on the partial steam pressure in the mixing chamber 1, which isproportional to the mole fraction of steam in the steam/air mixture. Inthe steam/air mixture fed into the mixing chamber 1 the actual amount ofair can be very low, but when a large part of the steam condenses in themixing chamber 1, the mole fraction of steam and air start to approacheach other and the partial steam pressure decreases. At the point wherethe declining saturation temperature of the steam meets the increasingproduct temperature, the equilibrium temperature is reached and heattransfer stops. This point can be determined from the ingoing flows byiterative calculation, so that the equilibrium temperature is known alsowhen no temperature sensor is present in the mixing chamber 1.

Even a very small fraction of steam in the steam/air mixture stillprovides a non-evaporative zone, enabling atomization at high drymatter. In tests with water the inventors found that a spray coming outof outlet nozzle 3 using pure air instead of steam is much coarser andcontains much larger droplets than when a very small amount of steam isadded. This indicates the steam effect on atomization.

By choosing a specific weight ratio of air to steam in the mixingchamber 1 and a specific temperature of the overheated steam a specificequilibrium temperature in the mixing chamber 1 can be set resulting ina specific temperature of the liquid composition present in the mixingchamber 1. Suitable equilibrium temperatures in the mixing chamber 1 canbe from 90° C. to 155° C. By spraying the liquid composition through theinlet nozzle 2 into the mixing chamber 1 and heating the sprayed liquidcomposition to the said equilibrium temperature, a first mixture FM isobtained. This first mixture is sprayed through the outlet nozzle 3. Atthis point a second atomization takes place. A force is created by thegas accelerating in the exit nozzle further breaking up the firstmixture into a fine spray which enters the drying chamber 6. The totalmass flow through outlet nozzle 3 is dependent from the pressure in themixing chamber 1 and the gas mass flow fraction.

By spraying the first mixture through the outlet nozzle 3 a secondmixture SM is obtained which can be dried by known means, for example bya heated air flow in the drying chamber 6 resulting in the evaporationof the liquid from the second mixture and the accumulation and shapingof a powdered composition. The powdered composition can be obtainedthrough an outlet 7.

Example 2

The apparatus and process shown in FIG. 1 and described in example 1 isused with following parameters:

The mixing chamber is fed with 21.2 kg/hour steam at a temperature of164° C. and 3.8 kg/hour air at a temperature of 170° C. A liquidcomposition having a temperature of 81.1° C. is sprayed into the mixingchamber in an amount of 326 kg/hour. The resulting pressure in themixing chamber is 6.5 bar. The partial pressure of the steam in themixing chamber is 5.85 bar. The resulting equilibrium temperaturepresent in the mixing chamber is 132° C.

Example 3

Test of Different Steam/air Ratios

A range of steam/air ratios was tested, starting from 100% air andending at 100% steam. A liquid composition and process settings asdefined in table 1 were used:

TABLE 1 liquid composition and process settings used in the example Fat% 28.3 Protein % 17.8 pH 6.5 Temperature of the liquid composition ° C.78 Flow of the liquid composition kg/h 332.0 powder production kg/h228.0 Dry matter content of the liquid % 67.2 composition

The steam, air and composition flows data where registered for eachsetting and from these values the equilibrium temperature inside themixing chamber was calculated. The product flow was found to be between304 and 337 kg/hour and the dry solids concentration of the emulsion was67%.

FIG. 2 shows the steam and air mass flows plotted at the calculatedequilibrium temperatures. In other trials where the equilibriumtemperature was not calculated, but measured inside the mixing chambersimilar results were found. This strengthens the reliability of usingcalculations for the determination of the equilibrium temperature.

When approaching 100% steam, as it was used in the state of the art, itwas found that it becomes more difficult to dry the powdered compositioncorrectly. The powdered composition got sticky and some lumps wereformed at the fluid bed.

FIG. 3 shows that the steam/air ratio has no strong influence on thebulk and particle density of the powdered composition. However, higherequilibrium temperatures lead to higher bulk and particle densities. Theexplanation of the trend is the fact that at lower temperatures, moreair is present in the gas mixture inside the mixing chamber and this aircan be incorporated in the product droplets during the secondatomization at the outlet nozzle. When using 100% steam there is no airat all present in the chamber. This results in droplets without includedair, resulting in higher densities. However, it is visible from FIG. 3that using the steam/air mixture according to the present inventionresults also in satisfying bulk and particle densities without thenegative side effects occurring when using steam only and the accordinghigh temperatures.

Furthermore, the producing rate for the powdered composition is muchhigher when using a steam/air mixture due to higher dry matter contentsbeing possible in the liquid composition.

Example 4

The process according to the present invention results in a powderedcomposition with a desired quality which can be produced in increasedamounts.

Furthermore, the obtained powdered composition has specific featuresmaking it distinguishable from powdered compositions produced byprocesses according to the state of the art.

FIG. 4 shows SEM pictures of the powdered composition according to thepresent invention (FIG. 4a ) and of a conventional powdered composition(FIG. 4b ).

The ivention claimed is:
 1. A process for the production of a powderedcomposition from a liquid composition comprising fat, protein or both,which process comprises: a) a first atomizing step comprising: i.feeding a mixture of gas and steam into a mixing chamber, and ii.feeding the liquid composition into the mixing chamber containing themixture of gas and steam by spraying the liquid composition through aninlet nozzle into the mixing chamber so as to obtain a mixture, whereinthe liquid composition is atomized through the inlet nozzle, and whereinthe mixture of gas and steam creates a non-evaporative zone in which thefeeding of the liquid composition into the mixing chamber takes placewithout simultaneous evaporation, b) a second atomizing step,comprising: i. spraying the mixture out of the mixing chamber through anoutlet nozzle and into a drying chamber, wherein the mixture is atomizedthrough the outlet nozzle and c) drying the mixture in the dryingchamber, so as to obtain the powdered composition.
 2. The processaccording to claim 1, wherein the gas is air.
 3. The process accordingto claim 1, wherein the liquid composition has a dry matter content from55 to 70 weight % based on total weight of the liquid composition. 4.The process according to claim 1, wherein the liquid composition has atemperature from 55 to 90° C. when sprayed into the mixing chamber. 5.The process according to claim 1, wherein the weight/hour ratio ofgas:steam in the mixing chamber is from 1:0.5 to 1:25.
 6. The processaccording to claim 1, wherein the weight/hour ratio of gas:steam:liquidcomposition in the mixing chamber is 0.5 to 5:2 to 15:100.
 7. Theprocess according to claim 1, wherein the equilibrium temperature in themixing chamber is from 90 to 155° C.
 8. The process according to claim1, wherein the liquid composition is sprayed into the mixing chamber ata flow-rate from 250 to 700 kg/hour.
 9. The process according to claim1, wherein the mixing chamber has a length of 2 to 10 cm.
 10. Theprocess according to claim 1, wherein the pressure in the mixing chamberis 2 to 10 bar.
 11. The process according to claim 1, wherein the liquidcomposition comprises fat, protein and carbohydrates.
 12. The processaccording to claim 1, wherein the liquid composition has a fat contentof 20 to 35 weight % based on dry weight of the liquid composition and aprotein content of 10 to 25 weight % based on dry weight of the liquidcomposition.
 13. A powdered composition, wherein the powderedcomposition is obtained according to the process of claim
 1. 14. Thepowdered composition according to claim 13, wherein the powderedcomposition has a particle size distribution D (v, 0.5) of 80 to 320 μm.15. The powdered composition according to claim 13, wherein the powderedcomposition has a particle size distribution D (4.3) of 80 to 350 μm.16. The powdered composition according to claim 13, wherein the powderedcomposition has a bulk density of 0.4 to 0.6 g/ml.
 17. A nutritionalproduct comprising the powdered composition according to claim 13, wherethe nutritional product is a food or feed product.
 18. The processaccording to claim 1, further comprising: collecting the powderedcomposition from the drying chamber through a recovery outlet.
 19. Aprocess for the production of a powdered composition from a liquidcomposition comprising fat, protein or both, which process comprises:spraying the liquid composition through an inlet nozzle into a mixingchamber containing a mixture of gas and steam having a gas:steam weightratio of from 1:0.5 to 1:25, wherein the mixture of gas and steamcreates a non-evaporative zone in which the spraying of the liquidcomposition into the mixing chamber takes place without simultaneousevaporation, and wherein the liquid composition is atomized through theinlet nozzle and heated by the mixture of gas and steam to generate amixture; spraying the mixture out of the mixing chamber through anoutlet nozzle and into a drying chamber, wherein the mixture is atomizedthrough the outlet nozzle; and drying the mixture in the drying chamberto generate the powdered composition.
 20. The process according to claim1, wherein feeding a mixture of gas and steam into the mixing chambercomprises separately feeding the gas and steam into the mixing chamber,the steam having a temperature of 164° C. into the mixing chamber at arate of 21.2 kg/hour and the air having a temperature of 170° C. intothe mixing chamber at a rate of 3.8 kg/hour.
 21. The process accordingto claim 1, wherein the gas comprises about 78 vol. % nitrogen, andabout 21 vol. % oxygen.